The math that they used to decide what rate would be assigned to which country is simple enough that a middle school student can do it, and If other countries believe that we're not just going to change the system next year, it gives those countries an incentive to reduce their trade surplus with us, so we can calculate a lower rate for the next year.
The goal in theory is to zero out all trade surpluses that other countries have with us or, saying the same thing a different way, to zero out all trade deficits that we have with other countries.
The problem is, you will find almost no economists who think that trade deficits matter, almost nobody with any kind of degree in economics thinks that it's important to reduce all trade imbalances. Further, even those who do think trade deficits are important, will admit that tariffs are not really the best tool to fix it. Non tariff barriers would be much more effective at changing trade totals.
Most progressives and liberals will short circuit their thinking there, and say Trump is dumb, Trump doesn't listen to experts, that's the end of the story.
That's not the end of the story. Trump's goal is not actually to "bring jobs back" or "fix trade deficits." While in theory over time, trade deficits could be fixed, and these tariff calculations could reduce down to zero, that would never happen by the end of Trump's term. If Trump can manage to keep these tariffs in place for the rest of 2025, they will raise a significant amount of revenue. He is then going to try to use that significant amount of revenue as an excuse to create new cuts in income taxes. That's his play. That's what Republican candidates for Congress are going to have to defend, unless they can persuade Trump to back off, or persuade enough of their colleagues to override Trump's vetoes and stop the tariffs that way.
The Democrats are going to, correctly, portray this as an attempt to take tax burden away from very wealthy individuals, and put it on consumers, aka less affluent people, instead.
The Republicans, if they choose not to resist Trump, will have to distract the public from the Democrats' arguments, or try to counter them by saying factories are opening, wages are going up, employment is going up, stuff like that. But what if factories aren't opening? What if wages aren't going up?

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